Fix Rails main integration tests

Two failures under Rails main (Ruby 4.0, SimpleCov 1.x):

SimpleCov 1.0 replaced the `running` accessor with `active_session?` and
deprecated `add_filter` in favor of `skip`, so the test app's test_helper
crashed with NoMethodError before any test could load. Both call sites now
pick the available API.

Rails main assigns ActiveSupport::LogSubscriber.logger once during boot
instead of falling back to Rails.logger on each event, so log subscribers
such as Lograge kept writing to the boot logger after LogStruct replaced
Rails.logger, and request logs bypassed the LogStruct appenders. The
initializer order that decides this is not guaranteed, which is why it only
reproduced on a freshly generated app.

Author: ndbroadbent

lib/log_struct/semantic_logger/setup.rb

@@ -221,6 +221,12 @@ def self.replace_rails_logger(app)
         # Replace Rails.logger
         Rails.logger = logger
 
+        # Rails assigns ActiveSupport::LogSubscriber.logger once during boot
+        # (in the active_support.set_log_subscriber_logger initializer), so log
+        # subscribers such as Lograge keep writing to the original boot logger
+        # unless this reference is updated along with Rails.logger.
+        ActiveSupport::LogSubscriber.logger = logger
+
         # Also replace various component loggers
         ActiveRecord::Base.logger = logger if defined?(ActiveRecord::Base)
         ActionController::Base.logger = logger if defined?(ActionController::Base)

rails_test_app/create_app.rb

@@ -356,7 +356,12 @@ def copy_template(file, target_path = nil)
         SimpleCov.start do
           root_path = File.expand_path('../../..', __dir__)
           coverage_dir File.join(root_path, 'coverage_rails')
-          add_filter '/rails_test_app/'
+          # SimpleCov >= 1.0 deprecated `add_filter` in favor of `skip`
+          if SimpleCov.respond_to?(:skip)
+            SimpleCov.skip '/rails_test_app/'
+          else
+            SimpleCov.add_filter '/rails_test_app/'
+          end
           enable_coverage :branch
           primary_coverage :branch
         end

rails_test_app/templates/test/integration/logging_integration_test.rb

@@ -4,6 +4,13 @@
 require "test_helper"
 
 class LoggingIntegrationTest < ActionDispatch::IntegrationTest
+  # Rails assigns ActiveSupport::LogSubscriber.logger once during boot, so log
+  # subscribers (Lograge, Active Record, Action Controller) write to that
+  # reference rather than looking up Rails.logger on each event.
+  def test_log_subscribers_use_the_logstruct_logger
+    assert_kind_of LogStruct::SemanticLogger::Logger, ActiveSupport::LogSubscriber.logger
+  end
+
   # Basic test to ensure the Rails app is working
   def test_healthcheck_works
     get "/health"

rails_test_app/templates/test/test_helper.rb

@@ -7,7 +7,15 @@
 require "open3"
 require "timeout"
 
-unless SimpleCov.running
+# SimpleCov >= 1.0 replaced the `running` accessor with `active_session?`
+simplecov_started =
+  if SimpleCov.respond_to?(:active_session?)
+    SimpleCov.active_session?
+  else
+    SimpleCov.running
+  end
+
+unless simplecov_started
   SimpleCov.formatters = [
     SimpleCov::Formatter::HTMLFormatter,
     SimpleCov::Formatter::JSONFormatter
@@ -19,7 +27,12 @@
     gem_path = File.expand_path("../../../../", __FILE__)
     SimpleCov.root(gem_path)
 
-    add_filter "rails_test_app"
+    # SimpleCov >= 1.0 deprecated `add_filter` in favor of `skip`
+    if SimpleCov.respond_to?(:skip)
+      SimpleCov.skip "rails_test_app"
+    else
+      SimpleCov.add_filter "rails_test_app"
+    end
 
     coverage_dir "coverage_rails"